Device for permanently joining objects



April 10, 1956 wo t 2,741,069

DEVICE FOR PERMANENTLY JOINING OBJECTS Filed April 18, 1955 5Sheets-Sheet l 57 INVENTOR.

6 2 I250 AVOA/L Mfl/V BY W Va/"M AUTOQ/VEV April 1956 F. WOHLMAN2,741,069

DEVICE FOR PERMANENTLY JOINING OBJECTS Filed April 18, 1955 3Sheets-Sheet 2 April 1956 F. WOHLMAN DEVICE FOR PERMANENTLY JOININGOBJECTS 3 Sheets-Sheet 3 Filed April l8, l955 F260 (062 /4- Illa/V IN VEN TOR.

.QTTOAQ/VEL'V United States Patent DEVICE FQR PERMANENTLY JQENING GBJETSFred Wohlman, Ingievvood, Caiih, assignor to Hughes Aircraft Company,Quiver City, Calif., a corporation of Delaware Appiication April is,1955, Serial No. 501,851

11 Qiaims. (Si. ii -1) The present invention relates generally to adevice forpermanently joining objects and relates more specifically toan apparatus for use in the manufacture of semiconductor translatingdevices and for permanently attaching a glass bead or the like to anelongated wire lead. The assembly thus constructed serves thereafter toform one element of a partially assembled semiconductor translatingdevice.

In the manufacture of semiconductor translating devices such as, forexample, transistors of various types, diodes or rectifiers, photocelldevices and the like, it is important that all of the various componentsthereof be assembled in a precise manner inasmuch as relatively smallparts of such devices must accurately be positioned relative to otherparts in order that the resulting electrical value of the ultimatefinished product may be maintained at a high degree of accuracy.Additionally, most contemporary semiconductor translating devices employcomponents that are preferably encased in a hermetically sealed supportand surrounding structure, in order that the function thereof mayproperly be maintained following assembly of the necessarily relativelysmall components in semiconductor translating devices. Inasmuch asextreme accuracy must always be present, .precise positioning andalignment of the various components of the encasing structure must bemaintained, and in forming subassemblies of the encasing structure, thatare usually of glass, it is important that a time controlledelectrically heated fusing cycle be accurately provided.

Heretofore, in similar structures, serious difiiculties have beenpresented relative to accurate and precisepositioning and alignment ofend closure members for a semiconductor translating device on suitableleads extending from the devices. In order that high production maybemaintained, it is important that the rejection rate of improperlyconstructed subassemblies for semiconductor translating devices bemaintained at a low level commensurate with the necessity of handlingthe extremely small components that go to make up such translatingdevices. Not only must precise dimensional tolerances be held inpermanently attaching a bead to a wire lead as far as the diameter ofthe head is concerned and as far as the distance of the head from oneend of the lead is further concerned, but the physical connectionbetween the head and the lead must also constitute an intimate contactsituation in order to provide for the ultimate desired hermeticallysealed condition and proper fit and alignment with other components ofthe semiconductor translating devices. In light of the necessity formanual handling and placement of the relatively small semiconductortranslating device components in apparatus for construction subassemblythereof, and in view of the frangible nature of some of thesecomponents, consideration must also be given to the accessible nature ofmachines and subassembly forming apparatus, so as to aid the operator inmaintaining as high a production rate as possible. Prior arrangementsdesigned for a similar purpose have been manually difi'icult to operateand slow in operating char- As shown in Fig. 1, one

ice

acteristics, have failed to consider the requirements of an operatorthereof and have, additionally, failed to maintain the necessary andrequired precise tolerance limits for mass production situations.

Accordingly, the present device contemplates the provision of anapparatus that will serve to first support a wire lead having a glassbead manually positioned thereon, to align and position the bead at apredetermined distance from one end of the lead, efiect operation of aheating element over a predetermined period of time, and reset themachine for the next operational cycle thereof.

Accordingly, it is one important object of the present invention toprovide a novel device for permanently joining objects with each other.

It is another important object of the present invention to provide anovel device for permanently joining and fusing a glass bead withrespect to a wire lead, thus to construct a subassembly of asemiconductor translating device.

It is a further important object of the present invention 'to provide anapparatus 'for assembling subassemblies of semiconductor translatingdevices wherein novel means are employed to effect heating and fusing ofa glass head to a wire lead in accordance with a predetermined timedheating cycle.

Still another important object of the present invention is to provide adevice for manufacturing partially assembled semiconductor translatingdevices, wherein novel means are employed for supportingaligning andguiding such partially assembled components with suitable heating andglass fusing means in a manner enabling precise construction of thesecomponents.

A still further important object of the present invention is to provideanovel device for permanently joining objects, such as glass beads withwire leads, that is relatively simple in construction, has simplifiedoperating characteristics enabling operation by unskilled operators, isreliablein'use, eifective in operation and which requires very little,if any, continued maintenance.

Other and further important objects of the present invention will becomeapparent from the disclosures in the following detailed specification,appended claims and accompanying drawings, wherein:

Figure l is a perspective view showing the present device forpermanently joining one object with another;

Fig. 2 is a top plan view of the present device;

Fig. 3 is a front elevational view of the device with portions thereofbeing in section;

Fig. 4 is a transverse sectional view taken substantially as indicatedby line 4-4, Fig. 3;

Fig. 5 is an enlarged fragmentary sectional view showing the means forinitially positioning the bead on the lead, as taken substantially asindicated by line 5-5, Fig. 2; and Fig. 6 is a schematic wiring diagramshowin a typical electrical system that may be employed with the presentjoining device.

With reference to the drawings, the device of the present inventionincludes generally a base structure 10, a carriage 11, movably mountedon the base structure 19, a head or stationary portion 12 and a timerarrangement indicated generally at .13. As shown in Fig. 1, the basestructure 10 is designedpreferably to rest upon a supporting tray 14 orthe like, that may be made from any suitably resilient or flexiblematerial, for example, and which may contain a recessed tray portion 15in which components to be assembled by the present device may be placedfor ready access by an operator. end of the tray 15 may, .for

example, receive a plurality of wire leads "L while the for reception oflock nuts other end of the tray may contain a quantity of glass beads B.

groove 17 formed therein. The base of the groove 17 is provided withparallel secondary grooves 18 in which a pair of ways 29 are permanentlypositioned. The ways 20 have upwardly directed V-shaped grooves 21 inwhich a plurality of ball type rollers 22 are positioned. The

lateral ends of the groove 17 are fitted with transversely disposedmembers 23, Fig. 2, that are secured in position by means of recessedscrews 24, for example. The lower surfaces of the members 23 are adaptedfor engagement with the upper surfaces of the ways 20, thereby to limittravel of the rollers 22 in the grooves 21. The transverse members 23are provided with coextensive, inwardly directed adjustable stop membersin the form of screws 25 that 'threadably engage the members 23 andextend into the space defined by the groove 17. The stop members 25 areadaptedto be locked in position by means of lock nuts 26.

' The carriage structure 11 includes a base member 27 that is adapted tobe positioned in the groove 17 and to rest upon the ball type rollers22. The base member 27 is retained within the groove by means ofelongated bars 28 that are attached to the base body portion 16 by meansof screws 30 and extend over the upper surfaces of both the spacedefined by the groove 17 and side portions of the carriage basemember-.27. Lateral ends of the carriage base member 27 are adapted forengagement with the inner ends of the adjustable stop members 25,whereby to limit lateral movement of the carriage.

The carriage base member 27 has mounted thereon a-pair of lead :carryingblocks 31 and 32. The blocks .31 and 32 have upwardly and forwardlydirected beveled opposing facesv of the 7 surfaces 33, formingnotches inblocks, and further beveled surfaces 34. Shoulders 35 are definedbetween the lateral ends of the surfaces 33 and 34. The surfaces 33 areeach provided with laterally. extending grooves or elongated rectangularrecesses 36 in which a plurality of permanent magnets 37 are positioned;Each of the permanent magnets 37 is secured in position by means of ascrew 38, with the faces of the permanent magnets 37 being provided withI grooves or V-shaped slots 40. A pair of operating handles 41, ofinsulatory material, are secured on the surfaces 34 on the blocks 31 and32, by means of screws 42, with each of the handles 41 being providedwith hand or finger engageable portions 43 that extend over outer facesof the blocks 31 and 32. The hand engageable portions 43 each serve tosupport bead aligning structures indicated generally at 44, Fig. 5. Thestructures 44 each include a shaft 45 that is slidably journalled in atransverse portion 46 in each of the blocks 31 and 32, and are keyed toprevent rotation of the shaft with respect to the portion 46 by means,for example, of a threaded screw 47, the inner end of which is disposedin a longitudinal groove 48 in the shafts 45. The structures 44 areidentical with respect to each of the blocks 31 and 32 and accordingly,only a single one will be defined herein. The outer end of the shaft 45is reduced in diameter as at 50 and threaded as at 51 52. Thelock nuts52 are adapted for normal engagement with an inner surface 53 of thehandle portion 43. The outer end of the reduced diameter portion 50 isfitted with a button member 54 having-a reduced diameter portion 55,there being a compression spring 56 arranged between an outer surface 57of the handle portion 43 and the button 54 surrounding the reduceddiameter portion thereof. Upon manual movement of the button 54 in adirection to compress the spring 56, the nuts 52 will limit axialmovement of the shaft 45 by engagement thereof with an outer surface 59of the block 31. The end of the shaft 45 remote from the reduceddiameter portion 50 thereof is fitted diagonally with a plate member 58having a diagonally disposed edge surface 60 in which there is a pair ofV-shaped,

notches 61. Thus, upon depression of the button 54,

the plate member 58 will be moved inwardly from its normal positionagainst an inner surface 62 of the block 31, for a purpose to behereinafter more fully described.

As shown in Fig. 4, a generally U-shaped bracket 63 is mounted on thebase structure body portion 16 and secured thereto by means of screws 64and a pin 65. The bracket 63 serves to support a further generallyU-shaped insulatory member 66 on which the head12 is mounted. The head12 includes a body portion 67 that is mounted on the insulatory member66 by means of screws 68 and a guide pin 74 The head body pora tion 67extends from the bracket 63 to a position in an interference path oflateral travel of the carriage 11 and blocks 31 and 32 mounted thereon.The forward por:

tion of the head body portion 67 is provided with an angularly disposedsurface 71 in which a pair of generally rectangular open sided recesses72 are formed. The recesses 72 serve to receive and support a pair ofinsulating members 73 which are secured therein by means of screws 74that, in time, extend through plates 75 carried on the outer surface ofthe body 67 and adapted for engagement with the outer surfaces thereof,whereby adjustably to support the insulating members 73 inthe recesses72. The body portion 67 of the head 12 is further provided with a pairof laterally disposed bores 76 therethrough, in which heat resistantcups 77 of metal encased ceramic or the like are adapted to bepositioned. A pair ofcoiled electrically energizable heating elements 78are positioned within central openings in the cups 77, with leadstherefrom being attached to a plurality of elongated pin'shapedconnectors 89, carried by the insulating members 73. The connectors 89are slidably adjustably disposed in the insulating members 73, wherebyto permit accurate concentric positioning. of thecoiled heating elements78 within the cups 77. The outer exposed ends of the connectors 89 arecovered by means of a protective insulating cover member 81 that issecured in spaced relationship, to the outer surface 71 of the head bodyportion 67, by means of suitable screws 82, or the like. The lower endof the cover member 81 is curved over the lower end of the body 67,while the upper end thereof is open to provide an entrance forelectrical leads extending to the connectors 80, as will be hereinaftermore fully described.

As shown primarily in Fig. 2, a spacer 83 is mounted.

on one side of the base body portion 16,. there being a normally openswitch 84 carried thereby. The switch 84 is disposed over an uppersurface of one of the bars 28 and has a roller switch operatingstructure 85 carried thereby. A protruding screw 86, carried by a rearfully described.

7 With reference primarily to Fig. 6, the mechanism describedhereinbefore is connected to the suitable'timer mechanism 13 in a mannerto permit the necessity of only momentary closure of the switch S4 andthereafter provide a timed heating cycle for the coiled heating elements7 8. As shown, electrical energy is provided from a source throughsuitable leads 87 and 88, there being a master switch 90 in the lead 87.The lead 33 connects to oneside of the switch 84, there being a lead 91extending from the other side of the switch 84 to acoil 92 of a relay.The other side of the coil 92 is connected to a lead 93 extending to themaster switch 39. Upon momentary closure of the switch 84, by engagementof the screws 86 with the roller switch actuating'stlucture 35, the coil)2 will be energized, whereby to move an armature 94 in a direction toclose a pair of contacts 95 and'96. 'One of the contacts of the contactpair 95- is connected to a lead 97 extending to the input lead 88, withthe other of the contacts 95 being connected to a lead 98 which makescontact with a slidable contact structure 1% in the timer mechanism 13.A slidable contact structure, in the timer mechanism, is connected tothe other side of the switch 84 by means of a lead 101. Accordingly, thelead 97, contacts 95, leads 9% and 1&1 and slidable contact structure100 serve as a holding circuit to maintain energization of the coil 92following momentary closure of the switch 84. One of the contacts of thecontact 96 is connected by means of a lead 162 to the lead ?7, the otherof the contacts 96 being connected, by means of the lead 193, to adriving motor 194, the other side of the driving motor being connectedto the other side of the circuit by means of a lead 105 whichinterconnects with the lead 93. The motor 194 serves to drive themoveable contact structure 10% by means of a clutch 106, With the motor104, clutch 1&6 and moveable contact structure 160 being housed withinand forming portions of the timer mechanism 13. Simultaneously with theenergization of the motor 104, the coiled heating elements 73 are alsoenergized through leads 1b! and 138 that connect respectively with leads103 and 1%. Thus, upon momentary energization of the switch 84, the coil92 of the relay will be energized, with the circuit being maintained ina closed condition by means of the moveable contact structure 109. Themotor 104 will also be energized to drive the moveable portion of thecontact structure 169 toward the position indicated by the dotted linesthereof. When the moveable portion contact structure Elli) leaves thestationary contact thereof, the holding circuit for the relay coil 92will be interrupted, whereby to de-energize the coil 92. At this time, atension spring 11%, connected to the armature 94, will serve to open thecontacts 95 and 96 and thereby to de-energize the entire circuit.Additionally, a tension spring 111, connected to the moveable portioncontact structure it'll will reset the contact to the position shown bythe solid lines, preparatory to the next heating and bead fusing cycle.

In operation of the present device, an operatormanually places a bead Bon one of the leads L and thereafter positions the lead L in one of thegrooves 40 of one of the magnets 37. It is to be understood that theleads L are made from highly permeable metallic material. This operationis again repeated with respect to the other magnet carried on either theblock 31 or the block 32. The leads L are moved laterally along thegrooves 45 in the permanent magnet 37 until the inner ends thereof abutthe shoulder 55. The beads B are moved a considerable distance inwardlyon the lead L, so as to be in close approximation to the outer face ofthe plate 58. Thereafter, the button 54 is depressed, thus moving theplate away from the block face 62, with the V-shaped notches 61surrounding the leads L, whereby to move the beads B to the properpredetermined position from the outer ends of the leads L. The carriage11 is thereafter manually laterally moved by hand engagement with thehandle portions 43, so as to dispose the outer ends of the leads L,together with the beads B disposed thereon, through openings 112 in thehead body portion 67 and into the interiors of the coils of the heatingelements 7%. As described hereinbefore, movement of'the carriage 11 ineither direction Will energize the circuit to initiate action of thetimer mechanism 13 and provide energy for electrically heating the eleents 73. The leads L and beads B, previously placed upon an oppositecarriage block 31 or 32, may thereafter be removed and this now newlyexposed carriage block and permanent magnets carried thereby may befitted with additional leads and beads for the next fusing cycle. It isto be noted that the notches at), in the permanent magnets 37, providemeans for aligning the leads and the beads with the coils 78, and thatthe lateral end positions of the leads and beads withmthe coil 78 aredetermined by engagement of the carriage base 27 with the adjustablestop members 25. Thus, as

6 one pair of heads is being fused upon one pair of leads, another pairmay be prepared for fusion on the opposite block 31 or 32, with thetimed heating cycle being automatically provided by simple movement ofthe carriage 11 in a direction to dispose bead carrying outer ends ofleads in the coiled heating elements 7 3.

It may thus be seen that the present device provides novel meansfor'supporting, aligning and fusing glass beads on ends of wire leads ata predetermined distance from such ends of the wire leads. It may alsobe seen that the device of the present invention is designed forrelatively high mass production commensurate with the size of thecomponents being assembled thereby, and that the various components ofthe device are positioned in such a manner as to be readily accessibleby an operator thereof.

Having thus described the invention and the present embodiment thereof,it is desired to emphasize the fact that many modifications may beresorted to in a manner limited only by a just interpretation of thefollowing claims.

I claim:

1. In a device for permanently attaching a tubular member to anelongated member: a base structure; a carriage disposed for lateralreciprocal movement on said base structure; a stationary head mounted onsaid base structure; heating element means disposed in said head; meansoperatively associated with said carriage for supporting at least oneelongated member having a tubular member slidably disposed thereon; andmeans carried by said supporting means for permitting manual placementof said tubular member at a predetermined position on said elongatedmember, said carriage being adapted thereafter for manual reciprocalmovement to position at least a portion of said elongated member andsaid tubular member in heat inducing relationship with said heatingelement means, whereby to fuse said tubular member to said elongatedmember.

2. In a device for permanently attaching a tubular member to anelongated member: a base structure; a carriage disposed for lateralreciprocal movement on said base structure; a stationary head mounted onsaid base structure; coiled heating element means disposed in saidhead;.means operatively associated with said carriage for supporting atleast one elongated member having a tubular member slidably disposedthereon; and means carried by said supporting means for permittingmanual placement of said tubular member at a predetermined position onsaid elongated member, and for aligning said elongated member with saidheating element means, said carriage being adapted thereafter for manualreciprocal movement to position at least a portion of said elongatedmember and said tubular member in heat inducing relationship Within saidheating element means whereby to fuse said tubular member to saidelongated member.

3. In a device for permanently attaching a tubular member to anelongated member: a base structure; a carriage disposed for lateralreciprocal movement on said base structure; a stationary head mounted onsaid base structure; heating element means disposed in said head; meansoperatively associated with said carriage for supporting at least oneelongated member having a tubular member slidably disposed thereon;means carried by said supporting means for permitting manual placementof said tubular member at a predetermined position on said elongatedmember, said carriage being adapted thereafter for manual reciprocalmovement to position at least a portion of said elongated member andsaid tubular member in heat inducing relationship with said heatingelement means, whereby to fuse said tubular memberto said elongatedmember; and means responsive to said reciprocal movement or" saidcarriage for energizing said heating element means.

4. In a device for permanently attaching a tubular member to anelongated member: a base structure; a carriage'disposed for lateralreciprocal movement on said b'asestru'cture; a stationary head mountedon said base a V, 7 V

structure; heating element 7 means 'operatively associated with. saidcarriage for supporting at least one elongated member having a tubularmember slidably disposed thereon; means carried by said supporting meansfor permittingmanual placement of said tubularmember at a predeterminedposition on said elongated member, said carriage being adaptedthereafter for manual reciprocal movement to position at least a portionof said elongated member and said tubular member in heat inducingrelationship with said heating elementrmeans, whereby to fuse saidtubular member to said elongated member; and means including a timerarrangement and responsive to saidreciprocal movement of said carriagefor energizing said heating element means for a predetermined period oftime.

5. In a device for permanently attaching a tubular member to anelongated member: a base structure; a carriage disposed for lateralreciprocal movement on said base structure; a stationary head mounted onsaid base structure; coiled heating element means disposed in said head;means operatively associated with said carriage for supporting at leastone elongated member having a tubular member slidably disposed thereon;means carried by said a supporting means for permitting manual placementof said tubular member at a predetermined position on said elongatedmember, and for aligning said elongated member with said heating elementmeans, said carriage being adapted'thereafter for manual reciprocalmovement to position at least a portion of said elongated member andsaid tubular member, in heat inducing relationship within said heatingelement means, whereby to fuse said tubular member to said elongatedmember; and means including a timer arrangement and responsive to saidreciprocal movement of said carriage for energizing said'heating elementmeans for alpredetermined period of time.

6; A device for permanently attaching glass beads to elongated wiremembers comprising, in combination: a base structure; acarriage; rollermeans for supporting said. carriage for lateral reciprocal movement onsaid base structure; 'a plurality of heating elements; a supportingstructure for said heating elements, said supporting structure beingsecured to said base structure, said heating elements being laterallydisposed therein in parallel relationship; a pair of wire carryingmembers disposed on opposite ends of said carriage, said supportingstructure being disposed in an interference path therebetween; slidemeans operatively associated with each of said wire carrying members forpositioning a bead on each of several wire members at predetermineddistances from ends of said wire members, said carriage being adaptedthereafter for manual movement for disposition of said Wire members andsaid beads in said heating elements; and timer means, responsive to saidmanual movement of said'carriage, for energizing'said heating elementsfor apredetermined interval, whereby to fuse said beads to said wiremembers.

'7. A device for permanently attaching glass beads to elongated wiremembers comprising,lin combination: a

base structure; a carriage; roller means for supporting said carriagefor lateral reciprocal movement on said base structure; a plurality ofheating elements; a supporting structure for said heating elements, saidsupporting'structure being secured to said base structure; said heatingelementsbeing laterally disposed therein In parallel relationship; apair or" wire carrying members disposed on opposite ends of saidcarriage, said sup-' porting structure being disposed in an interferencepath therebetween; a plurality of permanent magnets carr ed by said wirecarrying members for retaimng said wlre members thereon; slide meansoperatively associated with each'of said Wire carrying members forpositioning a bead on each of several wire members at predetermineddistances from ends of said wire members, said carriage being adaptedthereafter for manual movement for disposition of said wire members andsaid beads in said means disposed insaidhead;

heating elements; and timer means, responsive to said base structure; acarriage; roller means cooperating with' ways in said base structure forsupporting said carriage for lateral reciprocal movement on said basestructure; stop means for limiting lateral movement of said carriage; aplurality of heating elements; a supporting structure of saidheating'elements, said supporting structure being secured to said basestructure, said heating elements being laterally disposed therein inparallel relationship; a pair of wire carrying members disposed onopposite ends of said carriage, said supporting structure being disposedin an interference path therebetween; stop means for one of the ends ofsaid wire members; slide means operatively associated with each of saidwire carrying members for positioning a head on each of several wiremembers at predetermined distances from the other of the ends of saidwire members, said carriage being adapted thereafter for manual movementfor disposition of said wire members and said beads in said heatingelements; and timer means, responsive to said manual movement of saidcarriage, for energizing said heating elements for a predeterminedinterval, whereby to fuse said beads to said wire members. V

9. A device for permanently attaching glass beads to elongated wiremembers comprising, in combination: a base structure; a carriage; rollermeans cooperating with 'ways in said base structure for supporting saidcarriage for lateral reciprocal movement on said base structure; stopmeans for limiting lateral movement of said carriage; a plurality ofheating elements; a supporting structure for said heating elements, saidsupporting structure being secured to said base structure, said heatingelements being laterally disposed therein in parallel relationship; apair of wire carrying members disposed on opposite ends of saidcarriage, said supporting structure being disposed in an interferencepath therebetween; a plurality of permanent magnets carried by said wirecarrying members for retaining said wire members thereon; stop means forone of the ends of said wire members; slide means operatively associatedwith each of said wire carrying members for positioning a bead on eachof several Wire members at predetermined distances from the other of theends of said wire members, said carriage being adapted thereafter formanual movement for disposition of said wire members of said beads insaid heating elements; and timer means, responsive to said manualmovement of said carriage, for energizing said heating elements for apredetermined interval, whereby to fuse said beads to said Wire members.a a a 10. A device for permanently attaching glass beads to elongatedwire members comprising, in combination: a base structure; a carriage;roller means for supporting said carriage for lateral reciprocalmovement on said base structure; a plurality of heating elements; asupporting structure for said heating elements, said supportingstructure being secured to said base structure, said heatingelementsbeing laterally disposed therein in parallel relat onship; a'pair of wire carrying membersdisposed on ment of said carriage in eitherdirection, for energizing.

said heating elementsfor a predetermined interval, whereby to fuse saidbeads to said wire members; and spring means for resetting said timermeans.

11. A device for permanently attaching glass beads to elongated wiremembers comprising, in combination: a base structure; a carriage; rollermeans cooperating with ways in said base structure for supporting saidcarriage for lateral reciprocal movement on said base structure; stopmeans for limiting lateral movement of said carriage; a plurality ofheating elements; a supporting structure for said heating elements, saidsupporting structure being secured to said base structure, said heatingelements being laterally disposed therein in parallel relationship; apair of wire carrying members disposed on opposite ends of saidcarriage, said supporting structure being disposed in an interferencepath therebetween; a plurality of permanent magnets carried by said wirecarrying members for retaining said wire members thereon; stop means forone of the ends of said wire members; slide means operatively 19associated with each of said wire carrying members for positioning abead on each of several Wire members at predetermined distances from theother of the ends of said Wire members, said carriage being adaptedthereafter for manual movement for disposition of said Wire members andsaid beads in said heating elements; momentarily energizable timermeans, responsive to said manual movement of said carriage in eitherdirection, for energizing said heating elements for a predeterminedinterval, Whereby to fuse said head to said wire members; and springmeans for resetting said timer means.

References Cited in the file or" this patent UNITED STATES PATENTS1,681,591 Millar Aug. 21, 1928 2,511,914 Haas June 20, 1950

